Effects of physical activity and acupuncture on calcitonin gene-related peptide immunoreactivity in different parts of the rat brain and in cerebrospinal fluid, serum and urine

Abstract

ABSTRACT

Calcitonin gene-related peptide (CGRP) is a very potent vasodilator in the nervous system, and maybe involved in hot flushes experienced by most women around menopause. Flushing post-menopausal women had higher urinary excretion of CGRP before than after successful treatment of their flushes with acupuncture. The prevalence of vasomotor symptoms is lower in physically active women. In a rat model we therefore intended to assess whether acupuncture and exercise affected CGRP concentrations in different parts of the brain and peripherally. The aim of the study was to elucidate the short- and long-term effects of exercise and acupuncture on CGRP concentrations in the nervous system of normal adult rats. In a rat model, we examined the effects of single interventions and long-term treatment with physical exercise and manual or electro-acupuncture on CGRP concentrations in urine, cerebrospinal fluid and serum and different parts of the brain. In all compartments studied, but significantly only in the cerebrospinal fluid, CGRP increased after a single session of physical exercise or electro-acupuncture. Manual acupuncture did not change CGRP concentrations in any compartment. Rats had the highest concentrations of CGRP in the pituitary and hypothalamus but the concentrations did not differ significantly between control rats and those subjected to long-term treatment with manual or electro-acupuncture or running rats. Rats treated with electro-acupuncture had twice the CGRP concentration in the frontal cortex compared to control rats, albeit the difference did not reach statistical significance. Evidently manual and electro-acupuncture have different effects, whereas electro-acupuncture and physical exercise have more similar effects on CGRP production and/or release. To elucidate the role of CGRP in vasomotor symptoms, further studies with older flushing rats should be performed.